An investigation on shear properties of woven fabrics by bias-extension test

External forces cause deformations on fabrics and define their mechanical properties. . In this study, woven fabrics having different weave types with different weft settings and their shear properties such as shear angle, breaking load, and extension at bias direction were investigated by bias-extension test. A new geometrical model was proposed to predict the shear angle of deformed fabrics from bias-extension test results. An experimental study was also carried out and shear angle of fabrics was measured on captured images of deformed fabrics. It was found that the shear angle results found by the new geometrical model were close to experimental results. Besides, tensile properties of fabrics along warp and weft directions were tested. Breaking load and extension results of bias-extension and tensile tests were discussed statistically depending on the structural parameters. It was observed that the direction of the force and structural properties of fabrics affect the load-extension results

Modelling the cross-sectional properties of yarn along the fabric

© 2019 Slovak University of Technology in Bratislava. All rights reserved.Three dimensional (3-D) fabric geometry defines the fabric’s physical and mechanical properties. For this reason, it is important to obtain realistic fabric models. In this study, the yarn path of the woven fabric was modeled according to structural properties of fabric using Pierce geometry. On the other hand, the cross-sectional properties of the yarn along the weave unit were modeled depending on the movement of the yarn and the interactions between adjacent and perpendicular yarns. The yarn path was divided into regions and the cross-section of the yarn was defined according to region properties. By an experimental study, the variation of the yarn dimension at each region was measurement and the flattening ratio of yarn was determined. These data were used in the cross-section model. The simulations of yarn path and cross-sectional models were obtained by using SolidWorks. These simulations present the variation of yarn cross-section along the weave unit

The relationship between the bagging deformation and air permeability performance of woven fabrics

In this study, an experimental study-was carried out in order to investigate the effects of bagging deformation of the fabric to the air permeability performance. In this study, a modified test apparatus was integrated to the Instron and fabrics having different structural properties were deformed by four different bagging test methods. The air permeability properties of tested fabrics were Measured before and shortly after bagging deformation tests. The results were discussed depending on the effect of test parameters and structural properties of the fabrics by statistical methods. The results showed that the structural properties of fabric determined the deformation and permeability properties of the fabrics. The test parameters; especially waiting time, were effective at the deformation degree and increase of the air permeabilit

An investigation on the bagging load of different woven fabrics

In this study, an experimental study was carried out in order to investigate the bagging deformation of different woven fabrics. The bagging behaviour of fabrics was evaluated by investigating the bagging load of fabrics depending on fabric properties such as weave type and settings. Besides different test procedures were applied and the effect of test parameters was discussed statistically. The availability of image analyse method to define the fabric deformation was also studied. For this purpose the cover factor of deformed and un-deformed fabric images was investigated by image analysis method in order to analyses the deformation degree. The weave type and settings are effective in the 3-D fabric geometry and also identified the 3-D bagging load of the fabric. Besides this, it was observed that the bigger sphere diameter and waiting time of the load onto the fabric increased the bagging deformation

A generalised geometric model for the determination of shear angle during the bias-extension test

The angle between warp and weft yarns of woven fabric changes during the shear mechanism and this behaviour affects the drape, bending, tensile, forming and handle properties of the product. It is therefore important to estimate this shear angle when designing woven fabric. This study aims to propose a new generalised model to estimate the shear angle of fabrics having different sample sizes and different structural properties. An experimental study was designed to investigate both the effect of sample size and structural parameters of fabric on the bias-extension test results. Firstly, five different sample sizes were tested for a defined fabric type. Then, three fabrics having two different weave types and two different settings were tested with two test lengths. The shear angle results found by the new generalised geometric model, the formula is given in the literature and the experimental measurements were compared. The results of the proposed model are close to the measured ones. In addition, it has been observed that fabric properties such as weave type and setting have considerable effects on the shear behaviour of fabrics

Effect of Self- Stitched Double Fabric's Properties on Tensile and Permeability Performances

The double fabrics having a complex structure are used in different areas both technically and aesthetically. In this study, tensile and air permeability properties of self-stitched double fabrics were investigated. Firstly, six different self-stitched double fabrics having the same yam type, same settings, two different weave types, and three different stitching arrangements were designed and manufactured. Then, the tensile properties of these double fabrics were tested by applying tensile test at warp and weft directions, and bias-extension test at 45 degrees bias direction. The effect of structural properties on tensile and air permeability results was discussed statistically. The tensile properties of self-stitched double fabrics having plain weave types are mostly better than 2/2 twill ones. The differences between tensile properties of self-stitched double fabrics generally were not found statistically significant according to stitching arrangement except the double fabric having plain weave type and higher stitching points. On the other hand, the differences between air permeability properties of all self-stitched double fabrics were found statistically significant at 95 % confidence level in terms of both stitching arrangement and weave type